Multiple-input and multiple-output (MIMO) technology is the use of multiple antennas at both one or more transmitters and one or more receivers. A MIMO system can be used to increase data throughput and link reliability of a network without increasing bandwidth frequencies or increasing transmit power of the network. To achieve the increased data throughput and link reliability, the data communicated between a node and a mobile device can be spread over the multiple antennas to achieve an array gain that improves the spectral efficiency and achieve a diversity gain that increases the link reliability. Massive MIMOs can deploy a large number of elements in antenna arrays. Multiple terminals can be deployed for combining a massive MIMO technology with conventional time and frequency division multiplexing using orthogonal frequency division multiplexing (OFDM).
Three-dimensional (3D) or full-dimensional (FD) MIMO systems can be used in MIMO networks to enhance the cellular performance by deploying antenna elements in both horizontal and vertical dimensions, e.g. a two dimensional (2D) antenna array. A FD MIMO system can direct communications in two dimensions, i.e. horizontally and vertically, to a location in three dimensional (3D) space. The direction of communications in 3D space can increase the directionality, allowing for increased numbers of communication paths, more focused beamforming, and increased throughput for spatial multiplexing in comparison with traditional two dimensional MIMO systems.
Reference will now be made to the exemplary embodiments illustrated, and specific language will be used herein to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended.